1. Field of the Invention
The present invention relates to an electrophoretic display and method thereof. More particularly, the present invention relates to an electrophoretic display capable of improving display characteristics thereof and the method thereof.
2. Description of the Related Art
In general, display apparatuses convert data in electric format, processed in an information processing unit, into image data and display the image data that are easily recognized visually. As one type of display apparatus, an electrophoretic display (“EPD”) has a thin thickness and a light weight in comparison with other display devices such as a cold cathode ray tube (“CRT”) display device, a liquid crystal display (“LCD”), etc.
Particularly, an EPD includes lower and upper substrates each on which electrodes are respectively arranged, and particles interposed between the lower and upper substrates. The particles are electrified to have a polarity, and move to the lower or upper substrate in accordance with an electric field applied between the lower and upper substrates. A phenomenon that the electrified particles move in accordance with the electric field is called an electrophoretic phenomenon, and the EPD displays the electrophoretic phenomenon of the particles. Since the EPD is a reflection type of display apparatus that displays an image using an external light, it does not need to have a separate light source. Further, the EPD has advantages of thin thickness and light weight since a layer constituted by the particles is thin.
However, when a full-color operation is performed, the chroma of pure color becomes lower and the image becomes indistinct, fuzzy and unclear because the EPD uses the external light. More specifically, in the EPD, red, green and blue pixels constitute one dot, and colors of the red, green and blue pixels in the dot are mixed with each other to display the image. Recently, an EPD to which a white pixel is added into the dot has been developed. In general, gray-scale values of the red, green and blue pixels are calculated from image data, and a gray-scale value of the white pixel is calculated from a smallest gray-scale value among the red, green and blue gray-scale values.
However, in a case of pure colors such as red, green and blue, since one of the red, green and blue pixels has a gray-scale value of zero, the gray-scale value of the white pixel is fixed to zero when the pure colors are displayed. Consequently, the pure colors displayed on the EPD become indistinct, and a display quality of the EPD is deteriorated.